Apparatus for dry drilling of bore holes



Feb. 11, 1958 A. P. c. STENUICK 2,323,013

APPARATUS FOR DRY DRILLING OF BORE HOLES Filed Sept. 19, 1952 2 sets-Sheet 1 ANDRE PIERRE CAMILLE STENdIcK- Feb. 11, 1958 A. P. c.STENUICK APPARATUS FOR DRY DRILLING OF BORE HOLES 2 Sheets-Sheet 2 FiledSept. 19, 1952 4 a m I,

ANDRE PIE RR; can 'LLE Srsu ulck United States Patent APPARATUS FOR DRYDRILLING OF BORE HOLES Andr Pierre Camille Stenuick, Eveque, BelgiumApplication September 19, 1952, Serial No. 310,508

Claims priority, application Belgium September 26, 1951 3 Claims. (Cl.2553) This invention relates to drilling and boring equipment, and moreparticularly to apparatus for drilling bore holes of large diameter andgreat depth.

In the drilling of bore holes of large diameter and great depth, severalmethods have been employed in the past,

to wit:

(1) Rotary drilling which yields bore holes of great depth but is slowand very costly.

(2) Boring with the bit which utilizes a tool of large diameter drivenin by a succession of violent thrusts.

The rate of advance is slow and, when the rock is hard,

the cutting edge of the bit is blunted rapidly so that the operationwears out a large number of tools.

(3) Boring with long borer or jumper of large diameter wherein thejumper bit is driven by a pneumatic or electrical hammer striking lightblows at a very rapid rate. This method permits sinking the hole atconsiderable speed, but does not permit reaching depths sufiicient forpurposes of modern rock penetration; a depth of 12 meters is at presentconsidered the maximum obtainable in the current practice of thisprocess. I

In all these methods, the apparatus which directly controls thebore-hole-drilling operation is located in the open, above ground.

Up to now large drilling depths could not be attained because the massof the jumper bit and its accessories absorbed almost by itself theblows struck by the hammer, with the result that the impact ultimatelyconveyed to the rock'to be disintegrated was very much reduced. On theother hand, the supply of air through the interior of the joint rodssupporting the jumper bit, which is needed for expelling the debrisderiving from the drilling operation and collecting at the bottom of thehole, is insufficient for an efiective removal of this debris. Lastly,boring to great depths necessitates an assembly of bars or rods which isextremely fragile at every joint because of the transmission of impactsover the entire length of the rod assembly.

It is the principal object of the invention to eliminate these drawbacksand to provide improved drilling equipment well adapted for bore holesof large diameters and greatdepth, and capable of operating at highspeed, low cost and increased efiiciency. I

.Otherobjects, and the manner in which the same are attained, willbecome apparent as this specification proceeds.

According to one of its aspects, the invention contemplates disposingthe percussion apparatus or hammer right above the bit so that it isintroduced into the bore hole and de'scendstherein as the workprogresses, in such manner that it advances immediately after thebitwhich. it actuates and is located at all times in close proximity tothe very bottom of the bore hole.

This descent or sinking is accomplished by the successive addition ofcoupled tubes the weight of which can be counterbalanced, for example,by counterweights.

In the drawing accompanying this specification and forming part thereof,one embodiment of the invention is illustrated diagrammatically by wayof example.

.HCC

In the drawing:

Fig. 1 is a schematic side view, partly in vertical section, of drillingequipment according to the invention;

Fig. 2 shows, in vertical section, the lower extremity of the equipmentshown in Fig. 1, drawn to a larger scale;

Fig. 3 shows, in vertical section, a hammer-and-bit assembly accordingto the invention; and

Fig. 4 is a bottom view of the assembly shown in Fig. 3.

According to this invention the percussion device is progressivelyintroduced into the deepening bore hole and has a diameter smaller thanthe largest diameter of the bit. The device penetrates into the borehole directly following the bit 15 which it actuates, and the casing ofthe device is rigidly connected with a first tube 4' to which may beadded one or more extension tubes by suitable joints.

When the hammer or ram 20 is of the pneumatically driven type, as moreparticularly disclosed herein, the compressed air required for itsactuation is supplied through the interior of the tubes supporting thepercussion device. This percussion device is equipped, in 31C- cordancewith a feature of this invention, with an air distribution system ofknown construction whereby the exhaust air is intermittently dischargedthrough the boring bit 15, e. g. by way of a central channel 24 asillustrated in Fig. 2 or near the periphery of the bit between itscutting edges as shown in Figs. 3 and 4. This air, accordingly, servesto evacuate from the bore hole 40 the dust and debris accumulating atits bottom in the course of the disintegration of the soil material bythe percussive action of the bit.

In the embodiment of Figs. 1 and 2 a carriage 8 is arranged fordisplacement on the ground S. This carriage' is provided with a verticalrail 9 slidably supporting a frame member 10 which is integral with agear box 11; the latter is coupled via a transmission 14 to a dependingtube 4' extending downwardly toward the casing 13 of the percussiondevice. The gear box 11 encloses mechanism known per se for rotating thetube 4' with the casing 13, the ram 20 and the bit 15 which latter ismounted on a short stem 2'.

A cable 16 is secured to frame member 10 and passes over a pulley 17mounted on top of the rail 9; the free end 39 of the cable 16 isprovided with means for supporting a counterweight 18. Thiscounterweight is so chosen that it balances the successive increase inweight of the coupled tubes when one or more extensions are added totube 4. Evidently, the Weights to be added to counterweight 18 shouldcorrespond to the weight of the added extension tube or tubes in orderto provide a percussion tool which exerts a constant static pressure, asindicated by arrow 42, upon the bottom of the hole 40. Compressed air issupplied to the ram 20 within cylinder 13 by way of tube 4' from asuitable source not shown.

In Fig. 2 the piston or ram 20 is provided with a piston rod 21 arrangedto act on the rod-like integral extension 22 of bit 15. The distributorfor the operating air has been indicated diagrammatically at 23. Inoperation, the arr 1s admitted to the interior of cylinder 13alternately above and below the ram, in a manner more fully describedhereinafter, and is intermittently expelled through channel 24 to clearout fragments of solid material from the bore hole as itleaves thelatter through the annular clearance provided between the wall of thehole and the outer surface of the cylinder 13.

In Figs. 3 and 4 there is shown a cylinder head 26 which is rigid withtube 4 and extends downwardly toward a junction with cylinder 13 ontowhich it is screwed. The interior of this cylinder accommodates the bit15 which in this instance, as best seen in Fig. 4, is equipped with fourblades 27.

The distributor, here designated 29, comprises a disk 30 adaptedalternately to open and to close a passage 31 establishing a pathbetween the space 33 above ram 20 and an annular chamber 34 receivingcompressed air from the tube 4. A conduit 35 establishes communicationbetween the space 33 below the ram 20 and the space 50 above disk 39which in turn communicates with the annular distributor chamber 34. Thisconduit 35 extends from an opening 53, located in the upper part ofdistributor 29, to another opening 5'4 located directly above the drillbit 15.

In order that the exhaust air after operating the ram may be utilized inthe cleaning of the bore hole and in the evacuation of debris, exhaustconduits 36 are provided in the wall of the cylinder 13 which extenddownwardly and have their exit orifices 41 between the blades 27 of thebit 15. Apertures 37 establish communication between the space 32 belowthe ram 20 and the conduits 36.

The disk 3d rests loosely on a ring-shaped collar 51. A passage 52connects the central distributor chamber 50, located above disk 30, withthe opening 53 in the cylinder shell.

With this arrangement the evacuation of debris from hole 4% is efiectedby successive, sudden expansions of compressed air which is expelled bythe ram after having actuated the same. The mode of operation is asfollows:

As the ram 2th rises, the space 32 above it is connected with theopening 53, located above disk 30, and with the annular distributorchamber 34. Passage 31, located under the disk Ed, is shut oil by thelatter. Because of the higher pressure prevailing in space 32, the ram20 is driven further upwardly and, toward the end of its stroke,uncovers the apertures 37 which permits the air present under the ram toescape by way of these apertures and conduits 36.

Upon completion of this upward stroke, the pressure of the aircompressed by the ram 20 in space 33 will exceed the pressure prevailingabove disk 39. As a result, the disk is raised and space 33 is therebyconnected with the annular chamber 34. The force of gravity and thehigher pressure obtaining in space 33 will drive the ram 2' forcefullytoward the bit 15 and the air contained in space 32 will be ejectedthrough apertures 37 and conduits 36.

As the ram reaches the end of its downward stroke, it covers theapertures 37 and compresses the air contained in space 32 until thepressure present therein exceeds the pressure prevailing below disk 36.This disk is then depressed and comes to rest on the ring-shaped collar51 which supports it. The ram then strikes the bit 15 and causes adeepening of the bore hole, whereupon the pressure in chamber 50 actsupon the lower surface of the ram 213 whose upper face is then underatmospheric pressure as the air above it is allowed to escape throughthe uncovered upper set of apertures 37. The difference in pressurecauses the ram to rise again and the cycle is repeated.

The air forced under pressure through the apertures 37 and the conduits36, at various stages of the cycle just described, will blow and ejectfrom the drilled bore hole the scrap produced by the action of the bit.The pressure increments occurring whenever the piston or ram reaches itstop and bottom positionswill give rise to strong pulsations in the ductsystem 13, 4', thus further facilitating the ejection of waste. Thesepulsations are propagated through tube 4' and its extensions so as todislodge any fragments that may have settled there, in this mannerpreventing any blocking of the air inlet passages.

Tests have shown that the herein described method of removing debris,grindings, chips and dust from the bottom of the bfife hole into theatmosphere is much more efiicient than the continuous blowing ofscavenger air through the bore hole and that it permits attaining boringdepths of as much as fifty meters.

5 wish to be understood that I do not desire to limit the invention tothe exact details of construction, design, method and operation shownand described inasmuch as numerous modifications, within the scope ofthe appended claims, will be apparent to persons skilled in the art.

} claim:

1. A drilling machine comprising an air pump, tubing adapted to belowered into a bore hole and intercommunicating with said pump, and adrill bit projecting from tubing, said tubing including a tubular endportion receiving the inner part of said bit and defining on itsinterior a cylinder chamber, said end portion having a series of boresparallel to the axis of said chamber and offset from said axis open atthe bottom adjacent the cutting part of the bit, each bore having apassage for intercommunicating interiorly with said chamber above saidinner part of said bit, a piston reciprocable in said chamber between alower position, wherein it covers said passages and makes impact withsaid inner part of said bit, and an upper position wherein it clearssaid passages, and means including an upper conduit delivering air abovesaid piston, a lower conduit delivering an below said piston at a pointnear the lower position thereof and valve means between said conduitsfor reciprocating said piston, whereby between each two succeedingimpacts of said piston with said bit air will be driven twice from saidchamber into said bores, the first time during the descent of the pistonbefore it covers said passages, and the sec- 0nd time during the ascentof the piston after it clears said passages.

2. A drilling machine as claimed in claim 1, wherein said outer part ofsaid drill bit includes intersecting edgecarrying arms angularly spacedapart from each other, said bores having their open bottoms disposedbetween said arms, whereby air will be delivered into the spaces betweensaid arms for directing an air blast towards said edges.

3. A drilling machine as claimed in claim 1, wherein the axes of all ofsaid bores are arranged along the periphery of a circle about the axisof said chamber, the diameter of said circle being slightly smaller thanthe width of said outer drill bit part, whereby the air will be directedin parallel streams eccentrically of the drill bit center towards theouter regions of the drill bit edges.

References Cited in the file of this patent UNITED STATES PATENTS1,408,975 Black Mar. 7, 1922 1,845,074 Billstrom Feb. 16, 1932 1,881,258Bayles Oct. 4, 1932 1,981,475 V Smith Nov; 20, 1934 2,033,527 Kitching eMarQlO, 1936 2,085,279 Tautenhahn June 29, 1937 2,241,712 McNamara May13, 1941 2,359,147 Merten Sept. 26, 1944 2,620,162 Pennington Dec. 2,1952 2,661,928 Topanelian Dec. 8, 1953 2,665,115 Bassinger Jan. 5, 1954OTHER REFERENCES High Drilling Rates Reported for Steam'-PoweredPercussion Drill, pages 167-168, Pit & Quarry, 1953, May edition.

